Regressions on master at commit r11-7569 vs commit r11-7559 on Linux/x86_64

[H.J. Lu]

New failures:
FAIL: g++.dg/modules/builtin-3_a.C -std=c++2b  scan-lang-dump module "Writing:-[0-9]*'s named merge key \\(decl\\) type_decl:'::__builtin_va_list'"
FAIL: g++.dg/modules/builtin-3_a.C -std=c++2b  scan-lang-dump module "Wrote GMF:-[0-9]* type_decl:'::__builtin_va_list'@builtins"
FAIL: g++.dg/modules/builtin-3_b.C -std=c++2b  scan-lang-dump module "Read:-[0-9]*'s named merge key \\(matched\\) type_decl:'::__builtin_va_list'"

New passes: